1. Field of Invention
The present invention relates to hand-holdable guns for longitudinally extruding a thermoplastic-type medium from a removable storage cartridge container therefor and heating means for use with such guns to facilitate said extrusion.
2. Description of the Prior Art
Several different types of prior art hand-holdable guns for enabling the longitudinal extrusion of a thermoplastic-type medium therefrom exist as do such guns in which heat is utilized to facilitate the extrusion of the thermoplastic-type medium from the gun, such as disclosed in U.S. Pat. Nos. 2,995,159; 3,204,828; 3,337,093; 3,281,576 and 3,776,426. Furthermore, such prior art type of hand-holdable longitudinal extrusion guns, also employ electric heating coils whose heat may be varied in order to vary the heat applied to the plastic material extruded from the gun, such as disclosed in U.S. Pat. No. 2,556,609. In addition, prior art longitudinal extrusion guns have also employed removable heating coils for facilitating the longitudinal extrusion of a thermoplastic-type medium from a storage container therefor, such as disclosed in U.S. Pat. No. 3,551,640. However, there are presently no prior art hand-holdable longitudinal extrusion type guns known to the Inventor having a removable heat sleeve therefor for facilitating the longitudinal extrusion of a thermoplastic-type medium from a storage container or cartridge therefor wherein a complete burst shield enclosure is provided for the cartridge within the heat sleeve for physically isolating the heat sleeve interior in the cartridge container to prevent fouling thereof in the event of burst of the cartridge container while enabling heating of the thermoplastic-type medium within the cartridge container to a controlled temperature. Furthermore, there are no such prior art longitudinal extrusion guns known to the Inventor in which a heat transfer plug is employed to prevent initial clogging of the extrusion outlet to facilitate flow therefrom. These disadvantages of the prior art are overcome by the present invention.